<?php
    // +----------------------------------------------------------------------
    // | TopThink [ WE CAN DO IT JUST THINK IT ]
    // +----------------------------------------------------------------------
    // | Copyright (c) 2015 http://www.topthink.com All rights reserved.
    // +----------------------------------------------------------------------
    // | Author: zhangyajun <448901948@qq.com>
    // +----------------------------------------------------------------------
    namespace think\process;
    class Utils {
        /**
         * 转义字符串
         * @param string $argument
         * @return string
         */
        public static function escapeArgument($argument) {
            if ('' === $argument) {
                return escapeshellarg($argument);
            }
            $escapedArgument = '';
            $quote           = false;
            foreach (preg_split('/(")/i', $argument, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE) as $part) {
                if ('"' === $part) {
                    $escapedArgument .= '\\"';
                } elseif (self::isSurroundedBy($part, '%')) {
                    // Avoid environment variable expansion
                    $escapedArgument .= '^%"' . substr($part, 1, -1) . '"^%';
                } else {
                    // escape trailing backslash
                    if ('\\' === substr($part, -1)) {
                        $part .= '\\';
                    }
                    $quote           = true;
                    $escapedArgument .= $part;
                }
            }
            if ($quote) {
                $escapedArgument = '"' . $escapedArgument . '"';
            }
            return $escapedArgument;
        }

        private static function isSurroundedBy($arg, $char) {
            return 2 < strlen($arg) && $char === $arg[0] && $char === $arg[strlen($arg) - 1];
        }

        /**
         * 验证并进行规范化Process输入。
         * @param string $caller
         * @param mixed  $input
         * @return string
         * @throws \InvalidArgumentException
         */
        public static function validateInput($caller, $input) {
            if (null !== $input) {
                if (is_resource($input)) {
                    return $input;
                }
                if (is_scalar($input)) {
                    return (string)$input;
                }
                throw new \InvalidArgumentException(sprintf('%s only accepts strings or stream resources.', $caller));
            }
            return $input;
        }
    }
